In recent years, computing devices equipped with “touch screens” have proliferated. A touch screen displays information for viewing by a user, such as outputs from an operating system or application executing on the computing device. A touch screen also serves as an input device, and can receive inputs via touches of the screen. The inputs may represent commands to the operating system, including commands to alter the display, or commands to an application providing information for display. The touch screen therefore enables a user to alter a display or interact with an application via touch.
Frequently, a user provides a touch input using a digit, such as a finger or a thumb, on one hand. Though, a user may provide input to the touch screen using any touch instrument, including a digit or a stylus
A computing device with a touch screen may be configured to recognize different types of touches, each characterized by a different pattern of contact with the touch screen. A touch's contact with the touch screen may include motion across the surface of the touch screen. For example, a “swipe” is a touch comprising an initial contact with the touch screen and a subsequent motion across the touch screen. Swipes include “drags” and “flicks.” “Drags” include relatively slow swipes and any swipes in which, after beginning the motion across the touch screen, the touch instrument stops moving (or decelerates to a low a speed) before losing contact with the touch screen. “Flicks” include relatively fast swipes.
A “pincer touch” is a touch comprising contact between the touch screen and multiple touch instruments, followed by movement of the touch instruments that changes the distance between the instruments' contact points with the screen. Pincer touches include “pinches” and “spreads.” A “pinch” is a touch comprising contact between the touch screen and multiple touch instruments, followed by motion that decreases the distance between the contact points, such as movement of the touch instruments' tips toward each other. By contrast, a “spread” is a touch comprising contact between the touch screen and multiple touch instruments, followed by motion that increases the distance between the contact points, such as movement of the touch instruments' tips away from each other.
A “tap” is a brief touch comprising initial contact between the touch instrument and the touch screen followed by loss of contact before a threshold time period has elapsed, without substantial intervening motion.
A “press” is akin to a tap, but with contact of longer duration. In particular, a press is a touch comprising initial contact between the touch instrument and the touch screen followed by loss of contact after a threshold time period has elapsed, without substantial intervening motion.
A computing device equipped with a touch screen may interpret some touch inputs as user commands to directly manipulate the display. “Direct manipulation” refers to a touch input that causes the computing device to alter the display in a way that responds to motion of the touch instrument(s)' contact point(s) across the screen.
In some direct manipulations, the displayed content will change in direct proportion to motion(s) of the contact points(s). For example, direct manipulation includes a pinch that reduces the magnification of the displayed content or a spread that increases the magnification of the displayed content. Direct manipulation also includes a drag that moves in a given direction across the touch screen and causes the displayed content to “pan” in the same direction and in correspondence to the contact point(s)' motion.
Though, a flick that causes the displayed content to pan in the same direction as the contact point(s)' movement and to continue panning after the touch instrument(s) lose contact with the touch screen (“panning with inertia”) is also a direct manipulation. In this case, the distance that the content pans and/or the duration of the period during which the content pans may be related to the speed (rather than the distance) of the contact point(s)' movement across the screen.
A touch may represent different commands to different applications. For example, in an image-editing application, a drag may correspond to a command to draw a curve from the starting point of the drag to the ending point of the drag. Likewise, dragging may signify selection of text to a word processing or web browsing application, while the same motion may signify navigational commands to a video game.
Various interfaces for altering the display of a touch screen have been proposed. For example, some applications allow the user to alter the display by touching a scroll bar or a navigational button associated with an application. Some devices allow the user to magnify at least a portion of the display by pressing a portion of the display or by tapping three touch instruments on the display.